Composição da fauna de Chrysomelidae (Coleoptera) no sudoeste do Paraná: em busca de indicadores ambientais e da história natural de espécies de Omophoita (Chevrolat, 1836) (Galerucinae, Alticini)

Abstract

Considered a biodiversity hotspot, the Atlantic Forest was a vast biome formed by a wide block of forests and since the Brazilian colonization it has been under great pressure with the increase of urban and agricultural areas. The southwest of Paraná belongs to this colonizing context, mainly from the 1940s onwards. As in other regions of Brazil and Paraná, the southwest had undergone selective exploitation of plant resources and, more recently, the conversion of natural environments into agricultural areas, making such environments highly fragmented, contributing to decrease in biodiversity due to the absence of favorable habitats. Furthermore, the species knowledge is insufficient, mainly on insects that inhabit the region. In this way, the inventory contributes to the understanding of distribution patterns, diversity, ecological relationships existing in ecosystems and the degree of preservation of these areas. From the basic information generated by the surveys, in addition to knowing the fauna present in the different places, it is also possible to seek to identify species that can serve as bioindicators. Beetles constitute a very diverse group, with wide geographic distribution, very abundant species, many of which are specialized in certain food sources and in different habitats. These characteristics, along with their natural history specificities, can qualify several species to be used as bioindicators. Among them, chrysomelids constitute one of the most diverse families of phytophagous beetles, with about 35,000 known species, of which 6,065 are recorded for Brazil. Aiming to know the diversity of Chrysomelidae species in southwestern Paraná, as well as the search for species that can be used as environmental indicators, in addition to the need for information on the natural history of species that are essential for understanding the role that each specie plays in the environment, this study is organized into three chapters. In the first, we carried out a study of the composition and structure of the Chrysomelidae community in two Atlantic Forest fragments in southwestern Paraná, seeking to verify species with potential for bioindication. A total of 3,472 specimens of Chrysomelidae belonging to seven subfamilies, 37 genera and 203 species were collected with malaise. Galerucinae had the greatest abundance and richness, followed by Cassidinae and Eumolpinae. Of all species sampled, five showed a fidelity index greater than 70% by Indval. Two species were considered characteristic: Omophoita octoguttata (Fabricius, 1775), Trichaltica sp.2; three species were considered detectors: Epitrix sp.1, Brasilaphtona sp.1 and Margaridisa sp. Omophoita octoguttata was considered with the possibility of being used in environmental monitoring, providing information on changes in the ecological status of the habitat. In the second chapter, taking into account the results obtained in the first, we studied the biology of Omophoita octoguttata (Fabricius, 1775) and Omophoita personata (Illiger, 1807) in the laboratory, expanding knowledge about their natural history. The bioassays were carried out based on the formation of 15 couples for each species obtained from parentals collected in the field. The parameters evaluated were longevity, fecundity, egg viability, fertility, number and duration of larval instars, duration of the pupal period, duration of the life cycle and behavioral aspects. The two species had three larval instars and the parameters evaluated were similar. However, the longevity of O. personata was greater than that of O. octoguttata. On the other hand, O. octoguttata had a longer period of development from egg to adult. And in the third chapter, we present the description of Laselva cleidae Rech & Linzmeier, 2020, a new species recently described, reinforcing the importance forestall fragments and the studies in these places. In this way, we bring important information about the fauna of a region that is still poor investigated and also about the natural history of species that are usually found in the field, but which remained little investigated.